Reading your post, made me remember about a solution which highlight, either, the foreground or the background, of files, with a specific extension, based on regular expressions.

I thought about highlighting the columns from position 73 to position 79. By that means, it would be been easy to see if text currently written, is before position 72, after position 79 or between these two locations !

This solution can be achieved by a modified python script, initially created by @claudia-frank, at the address, below :